The invention relates to rotary combustion engines, particularly to the type of rotary engine shown in U.S. Pat. No. 2,988,065 granted on June 13, 1961 to Wankel et al. Multi-unit engines of this type having a plurality of rotors journaled on a common shaft are also known. U.S. Pat. No. 3,077,867 granted Feb. 19, 1963 to Froede and U.S. Pat. No. 3,062,435 granted Nov. 6, 1962 to Bentele and U.S. Pat. No. 3,240,423 granted Mar. 15, 1966 to Jones, are examples of such prior art multi-unit rotary engines.
In the case of engines used to power automobiles, during a major portion of the time of engine operation, such an engine is operating at only part load which, in general, is even substantially less than half of maximum power operation. The efficiency of a combustion engine is substantially less at part load operation as compared to full load operation. Accordingly, when powering an automobile a combustion engine is operating at substantially less than maximum efficiency during a major portion of the time.